fuck.. I can think of a lot of things...
From small things like answering "whoever you feel comfortable with" instead of rattling off a list of other super hot girls I would like to have a threesome with when an ex-girlfriend asked the question of who I could see us having a threesome with
(her best friend, who was decent looking but not super hot, and her would have easily done it I found out later) to big things like deciding to go straight through school and try and become a philosophy professor instead of working in the gaming business.